Unmanned Aircraft System networks are a
special type of networks where high speeds of the nodes, long distances and
radio spectrum scarcity pose a number of challenges. In these networks, the
strength of the transmitted/received signals varies due to jamming, multipath
propagation, and the changing distance among nodes. High speeds cause another
problem, Doppler Effect, which produces a shifting of the central frequency of
the signal at the receiver. In this paper we discuss a modular system based on
cognitive to enhance the reliability of UAS networks.